156 THE DESCENT OF MAN. 



of the worst dispositions, which occasionally without any 

 assignable cause make their appearance in families, may 

 perhaps be reversions to a savage state, from which we are 

 not removed by very many generations. This view seems 

 indeed recognized in the common expression that such men 

 are the black sheep of the family. 



With civilized nations, as far as an advanced standard of 

 morality, and an increased number of fairly good men are 

 concerned, natural selection apparently effects but little; 

 though the fundamental social instincts were originally 

 thus gained. But I have already said enough, while treat- 

 ing of the lower races, on the causes which lead to the 

 advance of morality, namely, the approbation of our fellow- 

 men the strengthening of our sympathies by habit exam- 

 ple and imitation reason experience, and even self-inter- 

 est instruction during youth, and religious feelings. 



A most important obstacle in civilized countries to an 

 increase in the number of men of a superior class has been 

 strongly insisted on by Mr. Greg and Mr. Gal ton,* namely, 

 the fact that the very poor and reckless, who are often 

 degraded by vice, almost invariably marry early, while the 

 careful and frugal, who are generally otherwise virtuous, 

 marry late in life, so that they may be able to support 

 themselves and their children in comfort. Those who 

 marry early produce within a given period not only a 

 greater number of generations, but, as shown by Dr. Dun- 

 can,! they produce many more children. The children, 

 moreover, that are born by mothers during the prime of 

 life are heavier and larger, and therefore probably more 

 vigorous, than those born at other periods. Thus the 

 reckless, degraded, and often vicious members of so- 

 ciety, tend to increase at a quicker rate than 

 the provident and generally virtuous members. Or, as Mr. 

 Greg puts the case: "The careless, squalid, unaspiring 

 Irishman multiplies like rabbits; the frugal, foreseeing, 



*" Eraser's Magazine," Sept., 1868, p. 353. " Macmillan's Maga- 

 zine,'* Aug., 1865, p. 318. The Rev. F. W. Farrar (" Fraser's Mag.," 

 Aug., 1870, p. 264) takes a different view. 



f " On the Laws of the Fertility of Women," in " Transact. Royal 

 Soc.," Edinburgh, vol. xxiv. p. 287; now published separately under 

 the title of " Fecundity, Fertility and Sterility," 1871. See, also, 

 Mr. Qalton, "Hereditary Genius," pp, 352-357, for observations to 

 the above effect. 



